In the past, it has been known to surround a product, such as a food item for example, with a gas which is different in component or component proportions during a packaging or other process. This creates a preferred environment in which the food product resides within its package for such purposes as preservation, shelf life, freshness or other purposes.
Even more particularly, such treatment in the past has included flowing a gas, such as a gas containing a high nitrogen content, around a product or into a product container to at least partially separate the product from ambient atmosphere (which is ordinarily about 21% oxygen and 79% nitrogen, without limitation) and envelop in a modified atmosphere. In this manner, the container or package is then sealed, with the product thus encapsulated in a more preferred environment. Thus, ambient atmosphere is purged from the container or from around the product in favor of a more suitable gaseous environment.
In the past, such gassing is accomplished by flowing a desired gas onto or around a product or into a product container by means of rails, plates or other structures proximate the path of the products or the containers to which products are destined. Gas under pressure is presented to manifolds from where it flows through welded screens onto the product or into a container. One particular structure and process is described in U.S. Pat. No. 5,417,255, fully incorporated herein by reference. Another typical system is disclosed in U.S. Pat. No. 6,032,438, also fully incorporated herein by reference. Yet other prior systems also disclose gassing such as U.S. Pat. Nos. 5,816,024 and 7,412,811, also fully incorporated herein by reference. Yet other such systems are disclosed in United States Publication Nos. US2006/0231156 and US2006/0231157, likewise fully incorporated herein by reference. Such patents and publications are incorporated herein by this reference and made a part hereof as if fully set forth herein.
While these disclosures illustrate a variety of gassing systems, this present invention contemplates certain improvements relating to the gas flow itself. For example, it will be appreciated that the effective range and integrity of the gas flowing onto or toward the product or container is important, particularly when considering the potential interference of other processing or product handling or filling apparatus. For example, when the range of preferred gas flow of desired integrity is somewhat limited, the interference represented by these other structural features may make it impossible to generate the desired gas flow closely enough to the product or container to be sufficiently effective.
Accordingly, it is desired to provide a gas flow apparatus and methods having a greater range of preferred flow characteristics to enable desired gassing emanating from distances greater than heretofore attained.
It should be appreciated that while gas flow ranges may be theoretically affected or extended merely by increasing pressures or flow velocities, associated increasing turbulences may prevent the goal of increasing the desired range and may limit the effective range which otherwise may be theoretically attained. Even relative large variations in flow velocity between laminates of gas flow are detrimental to overall effective flow range as a result of boundary turbulence.
Accordingly, it is also desired to provide apparatus and methods for improving the parameters of gas flow characteristics emanating from a source so that increased effective range is attained without diminution of the integrity of the flow or gassing operations.